1. Field of the Invention
The invention relates to a switching power converter, and more particularly, to the control circuit of the flyback power converter with communication channel.
2. Description of Related Art
The flyback power converter had been widely used in the computers and home appliances. It provides an isolated power supply for the system. The technology of the flyback power converter is a well developed prior art. However, in recent development, a better power management is requested to meet the power saving requirements. The approach includes using the secondary side's control signal to control the primary side circuits. For example, for achieving a high efficiency operation and a low standby power, the CPU located in the secondary side should be able to control the output voltage of the PFC (power factor correction) converter located in the primary side. Besides, in order to report the power consumption of the system, the parameters such as the input voltage and the input current of the PFC converter should be reported to the CPU. Therefore, an isolated communication channel between the primary side and the secondary side is required.